Many devices exist that can reduce material to small particle sizes, but most are large, slow, heavy, and consume large amounts of energy. However, very few machines exist which can economically reduce particles down to very small fine particle sizes.
Grinding of materials to very small particles is carried out by a variety of machines. These machines employ two main processes. The first and most common, is by crushing the material between hard moving elements made from such materials as steel or silicates until the particles are of the required size. Repeated recycling may be employed to aid the process. Such machines are rolling, ball or hammer mills.
The second method is by employing high-energy impact. Machines using this principle cause high speed, hard moving elements, to collide with the particles to be ground. The particles to be ground are usually transported into and out of the impact area by gravity and by a gas, usually air. In some cases, material to be ground is carried only by gravity into the impact zone in the same way. As well as collisions with the grinding element, there are particle to particle collisions. However, these impacts make only a very small contribution because the particles are of much the same kinetic level and are moving in much the same direction. To achieve significant particle size reduction, recycling of the process must also be employed. A beater hammer mill is typical of such machines.
The crushing process is slow and usually limited in the mining and primary metallurgy industry. Impact grinding has the potential for fast throughput and great size reduction for other industrial and commercial particle grinding. The problem with present impact machines is that particle to particle impacts make only a small contribution, and hence the necessary energy level from the momentum transfer from the impacting elements must be at the highest energy necessary to break up the particles, that is the energy levels of the particles remain only as high as the initial impact.
A need therefore exists for a small, even portable machine that can achieve these results fast and economically.